The present invention relates to a system for protecting electronic components. More particularly, the present invention relates to a system for protecting electronic components from harsh environmental conditions that may exist in various industrial applications.
The importance of controlling and monitoring production processes using electronic devices and instrumentation requires at times, that the electronic instrumentation be located in the production environment. This places the electronic instrumentation in surroundings that may be harsh and this can often have a hazardous effect on the electronic components that they may not be capable of withstanding. For example, the electronic devices may be placed in a process that normally sustains saturation humidity that, over time, can severely damage and incapacitate the electronic components, if they are not properly protected.
Another problem occurs during plant cleaning or disinfection, which may require that the equipment used be cleaned with high pressure hot water. Water pressures greater than 600 psi may be used to clean equipment. This can be fatal to the electronic monitoring and control systems situated nearby. Such water pressures can easily penetrate most common rated electronic enclosures resulting in damage to the electronic circuitry contained within.
To overcome the problem, electronic components have been placed in hermetically sealed chambers that are designed to be waterproof. This technique is described in U.S. Pat. No. 6,075,204 to Celauro et al. This waterproof enclosure has proven successful under severely harsh conditions. The above-mentioned enclosure prevents condensation from forming inside the waterproof enclosure as the outside temperature decreases, eliminating damage to the electronics within. However, this system does not make a direct provision for the hermetically isolated satellite sensors connected to the system. Thus, the sensors are still subject to the same harsh environment, unless they are independently purged with a dry gas.
U.S. Pat. No. 5,603,892 to Grilletto et al. provides a gas purged electronics enclosure in which a control system is used to open and close valves in order to purge a contaminant-free gas through the electronics enclosure. In addition, a getter material is used as a scavenger to ensure the removal of contaminants. This patent describes a system that has only one enclosure for housing electronic components.
These prior art attempts do not provide a suitable and economical solution for protecting electronic devices that may be located in various places throughout a process and may be interconnected. What is needed is an integrated system that is capable of protecting these multiple interconnected electronic devices.
The present invention is an integral cascaded distributed purge system used to protect interconnected electronic components. The system is particularly useful in industrial applications where the surrounding environment can adversely affect electronic components. For example, in a food plant, cleaning procedures require that hot water and steam be used to wash down equipment. This creates an atmosphere where moisture can inadvertently enter into a sealed enclosure, ultimately leading to electronic failures. By installing the distributed purge gas system of the present invention, electronic devices located at different points in a process are protected by an integrated system that continuously purges pressurized gas through the system. This is accomplished in an efficient and cost effective manner, i.e. through already existing interconnecting cabling and fixtures.
The present invention provides a system that protects electronic components from the outside environment by means of continuously flowing pressurized gas through the system.
The system is capable of providing protection to the entire system of separately housed electronic devices from a single highly reliable source.
Accordingly, the present invention is a system for protecting electronic components from contamination, which comprises a tightly controlled, multi-tiered distribution means; a pressurized gas in fluid communication with the distribution means; a plurality of apparatuses for enclosing electronic devices connected to the distribution means; and each apparatus connected to the distribution means by a conduit having a first end and a second end, wherein the first end is connected to the distribution means and the second end is connected to the apparatus.
The present invention also includes a method of protecting electronic devices from contamination comprising the steps of: (a) enclosing at least one electronic device in an integrated distributed purge gas system comprising: (i) a distribution means, (ii) a pressurized gas in fluid communication with the distribution means, and (iii) a plurality of apparatuses which are capable of enclosing at least one electronic device, wherein the apparatuses are individually connected to the distribution means by means of a conduit, the conduit having a first end and a second end, wherein the first end is connected to the distribution means and the second end is connected to the apparatus; (b) continuously supplying to the system the pressurized gas; (c) maintaining a positive pressure within the system; (d) controlling flow and pressure very carfully at each stage; (e) continuously venting a portion of the pressurized gas; and (f) controlling the system to provide the precise amounts of gas necessary to enable the benefits of the system, while also preventing large amounts of purge gas from entering the plant environment in the event of multiple system failures.